Funnily enough, we're currently looking at Postgres vs MySQL at work, since Oracle seems to be sucking up higher and higher percentages of our budget, and we already use open source solutions to a lot of other problems, so it seems to make sense.

I haven't really used Postgres in about 4 years, but even then I preferred it to MySQL. It seems that in that time, while MySQL has made up for a lot of it's shortcomings, Postgres has continued to improve as well. It's now ever surpassed MySQL in the one thing it used to trail on - performance.

On top of that, Postgres is true open source, not backed by a company like MySQL. InnoDB (which is what gives MySQL a lot of it's improved data integrity) is closed source, and licensed from Oracle. What happens if Oracle decides to terminate that license?

The only thing is MySQL is deployed a lot more widely than Postgres (which is somewhat analogous to PHP and Perl). I'm using MySQL for a personal project of mine at the moment, because my hosting provider has it available by default. Maybe this will start to change, especially if MySQL ends up moving in a different direction in the hands of Sun.

I don't think I explained my point of view on that particularly well. What I meant was MySQL is backed by a single commercial interest (and as of this year, that commercial interest is a Big Corp). Somehow, someone has to make some money pretty directly off MySQL, and that someone has a lot of influence on the direction of MySQL. Much more than, say, IBM could ever have over the Linux kernel, despite the fact that they put money into it.

To me, that's a conflict of interest. Plus it creates uncertainty about what might happen in the future. Sun's already talking about closing the source of some of the tools (I doubt they will ever close MySQL completely, but still...). If there's a choice, I'll usually go for the OSS project that is not primarily controlled by a company. e.g. Perl over PHP, Debian over Red Hat.

I think you overestimate how much Sun controls MySQL. They have not made anything closed-source, and the stories that they were considering it a couple months ago were quite misleading. I think you're overestimating this in general actually. PHP is certainly not controlled by a company, and Fedora is a very open project.

Would it be any better if the top contributors to Postgres left the project than if the MySQL ones did? Unless you have some data showing that one project has a much more centralized group of contributors, I don't think you can draw any conclusions based on who makes money from it.

And, from what I understand, the licensing revenue is a pretty small part of the pie. Not surprisingly, the first three are the same ways that RT, Shadowcat, and Stonehenge makes their money. The Postgres Foundation makes money from donations. I suspect many of the organizations that the PG devs live in support themselves in similar ways as the companies previously mentioned. I know that this is the case for both MySQL and Perl and Ruby.

My criteria for good software:

Does it work?

Can someone else come in, make a change, and be reasonably certain no bugs were introduced?